Women's health refers to the health of women, which differs from that of men in many unique ways. Women's health is an example of population health, where health is defined by the World Health Organization as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". Often treated as simply women's reproductive health, many groups argue for a broader definition pertaining to the overall health of women, better expressed as "The health of women". These differences are further exacerbated in developing countries where women, whose health includes both their risks and experiences, are further disadvantaged.

Although women in industrialised countries have narrowed the gender gap in life expectancy and now live longer than men, in many areas of health they experience earlier and more severe disease with poorer outcomes. Gender remains an important social determinant of health, since women's health is influenced not just by their biology but also by conditions such as poverty, employment, and family responsibilities. Women have long been disadvantaged in many respects such as social and economic power which restricts their access to the necessities of life including health care, and the greater the level of disadvantage, such as in developing countries, the greater adverse impact on health.

Women's experience of health and disease differ from those of men, due to unique biological, social and behavioural conditions. Biological differences vary all the way from phenotype to the cellular, and manifest unique risks for the development of ill health.[1] The World Health Organization (WHO) defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity".[2] Women's health is an example of population health, the health of a specific defined population.[3]

Women's health has been described as "a patchwork quilt with gaps".[4] Although many of the issues around women's health relate to their reproductive health, including maternal and child health, genital health and breast health, and endocrine (hormonal) health, including menstruation, birth control and menopause, a broader understanding of women's health to include all aspects of the health of women has been urged, replacing "Women's Health" with "The Health of Women".[5] The WHO considers that an undue emphasis on reproductive health has been a major barrier to ensuring access to good quality health care for all women.[1] Conditions that affect both men and women, such as cardiovascular disease, osteoporosis, also manifest differently in women.[6] Women's health issues also include medical situations in which women face problems not directly related to their biology, such as gender-differentiated access to medical treatment and other socioeconomic factors.[6] Women's health is of particular concern due to widespread discrimination against women in the world, leaving them disadvantaged.[1]

A number of health and medical research advocates, such as the Society for Women's Health Research in the United States, support this broader definition, rather than merely issues specific to human female anatomy to include areas where biological sex differences between women and men exist. Women also need health care more and access the health care system more than do men. While part of this is due to their reproductive and sexual health needs, they also have more chronic non-reproductive health issues such as cardiovascular disease, cancer, mental illness, diabetes and osteoporosis.[7] Another important perspective is realising that events across the entire life cycle (or life-course), from in utero to aging effect the growth, development and health of women. The life-course perspective is one of the key strategies of the World Health Organization.[8][9][10]

Gender differences in susceptibility and symptoms of disease and response to treatment in many areas of health are particularly true when viewed from a global perspective.[11][12] Much of the available information comes from developed countries, yet there are marked differences between developed and developing countries in terms of women's roles and health.[13] The global viewpoint is defined as the "area for study, research and practice that places a priority on improving health and achieving health equity for all people worldwide".[14][15][16] In 2015 the World Health Organisation identified the top ten issues in women's health as being cancer, reproductive health, maternal health, human immunodeficiency virus (HIV), sexually transmitted infections, violence, mental health, non communicable diseases, youth and aging.[17]

Women's life expectancy is greater than that of men, and they have lower death rates throughout life, regardless of race and geographic region. Historically though, women had higher rates of mortality, primarily from maternal deaths (death in childbirth). In industrialised countries, particularly the most advanced, the gender gap narrowed and was reversed following the industrial revolution. [6] Despite these differences, in many areas of health, women experience earlier and more severe disease, and experience poorer outcomes.[18]

Despite these differences, the leading causes of death in the United States are remarkably similar for men and women, headed by heart disease, which accounts for a quarter of all deaths, followed by cancer, lung disease and stroke. While women have a lower incidence of death from unintentional injury (see below) and suicide, they have a higher incidence of dementia (Gronowski and Schindler, Table I).[6][19]

The major differences in life expectancy for women between developed and developing countries lie in the childbearing years. If a woman survives this period, the differences between the two regions become less marked, since in later life non-communicable diseases (NCDs) become the major causes of death in women throughout the world, with cardiovascular deaths accounting for 45% of deaths in older women, followed by cancer (15%) and lung disease (10%). These create additional burdens on the resources of developing countries. Changing lifestyles, including diet, physical activity and cultural factors that favour larger body size in women, are contributing to an increasing problem with obesity and diabetes amongst women in these countries and increasing the risks of cardiovascular disease and other NCDs.[11][20]

Women who are socially marginalized are more likely to die at younger ages than women who are not.[21] Women who have substance abuse disorders, who are homeless, who are sex workers, and/or who are imprisoned have significantly shorter lives than other women.[21] At any given age, women in these overlapping, stigmatized groups are approximately 10 to 13 times more likely to die than typical women of the same age.[21]

Women's health is positioned within a wider body of knowledge cited by, amongst others, the World Health Organisation, which places importance on gender as a social determinant of health.[22] While women's health is affected by their biology, it is also affected by their social conditions, such as poverty, employment, and family responsibilities, and these aspects should not be overshadowed.[23][24]

Women have traditionally been disadvantaged in terms of economic and social status and power, which in turn reduces their access to the necessities of life including health care. Despite recent improvements in western nations, women remain disadvantaged with respect to men.[6] The gender gap in health is even more acute in developing countries where women are relatively more disadvantaged. In addition to gender inequity, there remain specific disease processes uniquely associated with being a woman which create specific challenges in both prevention and health care.[18]

Even after succeeding in accessing health care, women have been discriminated against,[25] a process that Iris Young has called "internal exclusion", as opposed to "external exclusion", the barriers to access. This invisibility effectively masks the grievances of groups already disadvantaged by power inequity, further entrenching injustice.[26]

Behavioral differences also play a role, in which women display lower risk taking including consume less tobacco, alcohol, and drugs, reducing their risk of mortality from associated diseases, including lung cancer, tuberculosis and cirrhosis. Other risk factors that are lower for women include motor vehicle accidents. Occupational differences have exposed women to less industrial injuries, although this is likely to change, as is risk of injury or death in war. Overall such injuries contributed to 3.5% of deaths in women compared to 6.2% in the United States in 2009. Suicide rates are also less in women.[27][28]

The social view of health combined with the acknowledgement that gender is a social determinant of health inform women's health service delivery in countries around the world. Women's health services such as Leichhardt Women's Community Health Centre which was established in 1974[29] and was the first women's health centre established in Australia is an example of women's health approach to service delivery.[30]

Women's health is an issue which has been taken up by many feminists, especially where reproductive health is concerned and the international women's movement was responsible for much of the adoption of agendas to improve women's health.[31]

Women and men differ in their chromosomal makeup, protein gene products, genomic imprinting, gene expression, signaling pathways, and hormonal environment. All of these necessitate caution in extrapolating information derived from biomarkers from one sex to the other.[6] Women are particularly vulnerable at the two extremes of life. Young women and adolescents are at risk from STIs, pregnancy and unsafe abortion, while older women often have few resources and are disadvantaged with respect to men, and also are at risk of dementia and abuse, and generally poor health.[17]

Women experience many unique health issues related to reproduction and sexuality and these are responsible for a third of all health problems experienced by women during their reproductive years (aged 15–44), of which unsafe sex is a major risk factor, especially in developing countries.[17] Reproductive health includes a wide range of issues including the health and function of structures and systems involved in reproduction, pregnancy, childbirth and child rearing, including antenatal and perinatal care.[32][33] Global women's health has a much larger focus on reproductive health than that of developed countries alone, but also infectious diseases such as malaria in pregnancy and non-communicable diseases (NCD). Many of the issues that face women and girls in resource poor regions are relatively unknown in developed countries, such as female genital cutting, and further lack access to the appropriate diagnostic and clinical resources.[11]

Pregnancy presents substantial health risks, even in developed countries, and despite advances in obstetrical science and practice.[34]Maternal mortality remains a major problem in global health and is considered a sentinel event in judging the quality of health care systems.[35]Adolescent pregnancy represents a particular problem, whether intended or unintended, and whether within marriage or a union or not. Pregnancy results in major changes in a girl's life, physically, emotionally, socially and economically and jeopardises her transition into adulthood. Adolescent pregnancy, more often than not, stems from a girl's lack of choices. or abuse. Child marriage (see below) is a major contributor worldwide, since 90% of births to girls aged 15–19 occur within marriage.[36]

In 2013 about 289,000 women (800 per day) in the world died due to pregnancy-related causes, with large differences between developed and developing countries.[11][37] Maternal mortality in western nations had been steadily falling, and forms the subject of annual reports and reviews.[38] Yet, between 1987 and 2011, maternal mortality in the United States rose from 7.2 to 17.8 deaths per 100,000 live births, this is reflected in the Maternal Mortality Ratio (MMR).[38] By contrast rates as high as 1,000 per birth are reported in the rest of the world,[11] with the highest rates in Sub-Saharan Africa and South Asia, which account for 86% of such deaths.[39][37] These deaths are rarely investigated, yet the World Health Organization considers that 99% of these deaths, the majority of which occur within 24 hours of childbirth, are preventable if the appropriate infrastructure, training, and facilities were in place.[40][37] In these resource-poor countries, maternal health is further eroded by poverty and adverse economic factors which impact the roads, health care facilities, equipment and supplies in addition to limited skilled personnel. Other problems include cultural attitudes towards sexuality, contraception, child marriage, home birth and the ability to recognise medical emergencies. The direct causes of these maternal deaths are hemorrhage, eclampsia, obstructed labor, sepsis and unskilled abortion. In addition malaria and AIDS complicate pregnancy. In the period 2003–2009 hemorrhage was the leading cause of death, accounting for 27% of deaths in developing countries and 16% in developed countries.[41][42]

Non-reproductive health remains an important predictor of maternal health. In the United States, the leading causes of maternal death are cardiovascular disease (15% of deaths), endocrine, respiratory and gastrointestinal disorders, infection, hemorrhage and hypertensive disorders of pregnancy (Gronowski and Schindler, Table II).[6]

In 2000, the United Nations created Millennium Development Goal (MDG) 5[43] to improve maternal health.[44] Target 5A sought to reduce maternal mortality by three quarters from 1990 to 2015, using two indicators, 5.1 the MMR and 5.2 the proportion of deliveries attended by skilled health personnel (physician, nurse or midwife). Early reports indicated MDG 5 had made the least progress of all MDGs.[45][46] By the target date of 2015 the MMR had only declined by 45%, from 380 to 210, most of which occurred after 2000. However this improvement occurred across all regions, but the highest MMRs were still in Africa and Asia, although South Asia witnessed the largest fall, from 530 to 190 (64%). The smallest decline was seen in the developed countries, from 26 to 16 (37%). In terms of assisted births, this proportion had risen globally from 59 to 71%. Although the numbers were similar for both developed and developing regions, there were wide variations in the latter from 52% in South Asia to 100% in East Asia. The risks of dying in pregnancy in developing countries remains fourteen times higher than in developed countries, but in Sub-Saharan Africa, where the MMR is highest, the risk is 175 times higher.[39] In setting the MDG targets, skilled assisted birth was considered a key strategy, but also an indicator of access to care and closely reflect mortality rates. There are also marked differences within regions with a 31% lower rate in rural areas of developing countries (56 vs. 87%), yet there is no difference in East Asia but a 52% difference in Central Africa (32 vs. 84%).[37] With the completion of the MDG campaign in 2015, new targets are being set for 2030 under the Sustainable Development Goals campaign.[47][48] Maternal health is placed under Goal 3, Health, with the target being to reduce the global maternal mortality ratio to less than 70.[49] Amongst tools being developed to meet these targets is the WHO Safe Childbirth Checklist.[50]

Improvements in maternal health, in addition to professional assistance at delivery, will require routine antenatal care, basic emergency obstetric care, including the availability of antibiotics, oxytocics, anticonvulsants, the ability to manually remove a retained placenta, perform instrumented deliveries, and postpartum care.[11] Research has shown the most effective programmes are those focussing on patient and community education, prenatal care, emergency obstetrics (including access to cesarean sections) and transportation.[41] As with women's health in general, solutions to maternal health require a broad view encompassing many of the other MDG goals, such as poverty and status, and given that most deaths occur in the immediate intrapartum period, it has been recommended that intrapartum care (delivery) be a core strategy.[39] New guidelines on antenatal care were issued by WHO in November 2016.[51]

In addition to death occurring in pregnancy and childbirth, pregnancy can result in many non-fatal health problems including obstetrical fistulae, ectopic pregnancy, preterm labor, gestational diabetes, hyperemesis gravidarum, hypertensive states including preeclampsia, and anemia.[34] Globally, complications of pregnancy vastly outway maternal deaths, with an estimated 9.5 million cases of pregnancy-related illness and 1.4 million near-misses (survival from severe life-threatening complications). Complications of pregnancy may be physical, mental, economic and social. It is estimated that 10–20 million women will develop physical or mental disability every year, resulting from complications of pregnancy or inadequate care.[39] Consequently, international agencies have developed standards for obstetric care.[52]

Of near miss events, obstetrical fistulae (OF), including vesicovaginal and rectovaginal fistulae, remain one of the most serious and tragic. Although corrective surgery is possible it is often not available and OF is considered completely preventable. If repaired, subsequent pregnancies will require cesarian section.[53] While unusual in developed countries, it is estimated that up to 100,000 cases occur every year in the world, and that about 2 million women are currently living with this condition, with the highest incidence occurring in Africa and parts of Asia.[39][53][54] OF results from prolonged obstructed labor without intervention, when continued pressure from the fetus in the birth canal restricts blood supply to the surrounding tissues, with eventual fetal death, necrosis and expulsion. The damaged pelvic organs then develop a connection (fistula) allowing urine or feces, or both, to be discharged through the vagina with associated urinary and fecal incontinence, vaginal stenosis, nerve damage and infertility. Severe social and mental consequences are also likely to follow, with shunning of the women. Aprt from lack of access to care, causes include young age, and malnourishment.[11][55][53] The UNFPA has made prevention of OF a priority and is the lead agency in the Campaign to End Fistula, which issues annual reports[56] and the United Nations observes May 23 as the International Day to End Obstetric Fistula every year.[57] Prevention includes discouraging teenage pregnancy and child marriage, adeaquate nutrition, and access to skilled care, including caesarian section.[11]

The ability to determine if and when to become pregnant, is vital to a woman's autonomy and well being, and contraception can protect girls and young women from the risks of early pregnancy and older women from the increased risks of unintended pregnancy. Adequate access to contraception can limit multiple pregnancies, reduce the need for potentially unsafe abortion and reduce maternal and infant mortality and morbidity. Some barrier forms of contraception such as condoms, also reduce the risk of STIs and HIV infection. Access to contraception allows women to make informed choices about their reproductive and sexual health, increases empowerment, and enhances choices in education, careers and participation in public life. At the societal level, access to contraception is a key factor in controlling population growth, with resultant impact on the economy, the environment and regional development.[58][59] Consequently, the United Nations considers access to contraception a human right that is central to gender equality and women's empowerment that saves lives and reduces poverty,[60] and birth control has been considered amongst the 10 great public health achievements of the 20th century.[61]

To optimise women's control over pregnancy, it is essential that culturally appropriate contraceptive advice and means are widely, easily, and affordably available to anyone that is sexually active, including adolescents. In many parts of the world access to contraception and family planning services is very difficult or non existent and even in developed counties cultural and religious traditions can create barriers to access. Reported usage of adequate contraception by women has risen only slightly between 1990 and 2014, with considerable regional variability. Although global usage is around 55%, it may be as low as 25% in Africa. Worldwide 222 million women have no or limited access to contraception. Some caution is needed in interpreting available data, since contraceptive prevalence is often defined as "the percentage of women currently using any method of contraception among all women of reproductive age (i.e., those aged 15 to 49 years, unless otherwise stated) who are married or in a union. The “in-union” group includes women living with their partner in the same household and who are not married according to the marriage laws or customs of a country."[62] This definition is more suited to the more restrictive concept of family planning, but omits the contraceptive needs of all other women and girls who are or are likely to be sexually active, are at risk of pregnancy and are not married or "in-union".[37][63][58][59]

Three related targets of MDG5 were adolescent birth rate, contraceptive prevalence and unmet need for family planning (where prevalence+unmet need = total need), which were monitored by the Population Division of the UN Department of Economic and Social Affairs.[64] Contraceptive use was part of Goal 5B (universal access to reproductive health), as Indicator 5.3.[65] The evaluation of MDG5 in 2015 showed that amongst couples usage had increased worldwide from 55% to 64%. with one of the largest increases in Subsaharan Africa (13 to 28%). The corollary, unmet need, declined slightly worldwide (15 to 12%).[37] In 2015 these targets became part of SDG5 (gender equality and empowerment) under Target 5.6: Ensure universal access to sexual and reproductive health and reproductive rights, where Indicator 5.6.1 is the proportion of women aged 15–49 years who make their own informed decisions regarding sexual relations, contraceptive use and reproductive health care (p. 31).[66]

There remain significant barriers to accessing contraception for many women in both developing and developed regions. These include legislative, administrative, cultural, religious and economic barriers in addition to those dealing with access to and quality of health services. Much of the attention has been focussd on preventing adolescent pregnancy. The Overseas Development Institute (ODI) has identified a number of key barriers, on both the supply and demand side, including internalising socio-cultural values, pressure from family members, and cognitive barriers (lack of knowledge), which need addressing.[67][68] Even in developed regions many women, particularly those who are disadvantaged, may face substantial difficulties in access that may be financial and geographic but may also face religious and political discrimination.[69] Women have also mounted campaigns against potentially dangerous forms of contraception such as defective intrauterine devices (IUD)s, particularly the Dalkon Shield.[70]

Abortion is the intentional termination of pregnancy, as compared to spontaneous termination (miscarriage). Abortion is closely allied to contraception in terms of women's control and regulation of their reproduction, and is often subject to similar cultural, religious, legislative and economic constraints. Where access to contraception is limited, women turn to abortion. Consequently, abortion rates may be used to estimate unmet needs for contraception.[71] However the available procedures have carried great risk for women throughout most of history, and still do in the developing world, or where legal restrictions force women to seek clandestine facilities.[72][71] Access to safe legal abortion places undue burdens on lower socioeconomic groups and in jurisdictions that create significant barriers. These issues have frequently been the subject of political and feminist campaigns where differing viewpoints pit health against moral values.

Globally, there were 87 million unwanted pregnancies in 2005, of those 46 million resorted to abortion, of which 18 million were considered unsafe, resulting in 68,000 deaths. The majority of these deaths occurred in the developing world. The United Nations considers these avoidable with access to safe abortion and post-abortion care. While abortion rates have fallen in developed countries, but not in developing countries. Between 2010–2014 there were 35 abortions per 1000 women aged 15–44, a total of 56 million abortions per year.[41] The United nations has prepared recommendations for health care workers to provide more accessible and safe abortion and post-abortion care. An inherent part of post-abortion care involves provision of adequate contraception.[73]

Traditional African midwife explaining the risks of FGC for childbirth at a community meeting

Female genital mutilation (also referred to as female genital cutting) is defined by the World Health Organization (WHO) as "all procedures that involve partial or total removal of the external female genitalia, or other injury to the female genital organs for non-medical reasons". It has sometimes been referred to as female circumcision, although this term is misleading because it implies it is analogous to the circumcision of the foreskin from the male penis.[76] Consequently, the term mutilation was adopted to emphasise the gravity of the act and its place as a violation of human rights. Subsequently, the term cutting was advanced to avoid offending cultural sensibility that would interfere with dialogue for change. To recognise these points of view some agencies use the composite female genital mutilation/cutting (FMG/C).[76]

It has affected more than 200 million women and girls who are alive today. The practice is concentrated in some 30 countries in Africa, the Middle East and Asia.[77] FGC affects many religious faiths, nationalities, and socioeconomic classes and is highly controversial. The main arguments advanced to justify FGC are hygiene, fertility, the preservation of chastity, an important rite of passage, marriageability and enhanced sexual pleasure of male partners.[11] The amount of tissue removed varies considerably, leading the WHO and other bodies to classify FGC into four types. These range from the partial or total removal of the clitoris with or without the prepuce (clitoridectomy) in Type I, to the additional removal of the labia minora, with or without excision of the labia majora (Type II) to narrowing of the vaginal orifice (introitus) with the creation of a covering seal by suturing the remaining labial tissue over the urethra and introitus, with or without excision of the clitoris (infibulation). In this type a small opening is created to allow urine and menstrual blood to be discharged. Type 4 involves all other procedures, usually relatively minor alterations such as piercing.[78]

While defended by those cultures in which it constitutes a tradition, FGC is opposed by many medical and cultural organizations on the grounds that it is unnecessary and harmful. Short term health effects may include hemorrhage, infection, sepsis, and even result in death, while long term effects include dyspareunia, dysmenorrhea, vaginitis and cystitis.[79] In addition FGC leads to complications with pregnancy, labor and delivery. Reversal (defibulation) by skilled personnel may be required to open the scarred tissue.[80] Amongst those opposing the practice are local grassroots groups, and national and international organisations including WHO, UNICEF,[81] UNFPA[82] and Amnesty International.[83] Legislative efforts to ban FGC have rarely been successful and the preferred approach is education and empowerment and the provision of information about the adverse health effects as well the human rights aspects.[11]

Progress has been made but girls 14 and younger represent 44 million of those who have been cut, and in some regions 50% of all girls aged 11 and younger have been cut.[84] Ending FGC has been considered one of the necessary goals in achieving the targets of the Millennium Development Goals,[83] while the United Nations has declared ending FGC a target of the Sustainable Development Goals, and for February 6 to known as the International Day of Zero Tolerance for Female Genital Mutilation, concentrating on 17 African countries and the 5 million girls between the ages of 15 and 19 that would otherwise be cut by 2030.[84][85]

In the United States, infertility affects 1.5 million couples.[86][87] Many couples seek assisted reproductive technology (ART) for infertility.[88] In the United States in 2010, 147,260 in vitro fertilization (IVF) procedures were carried out, with 47,090 live births resulting.[89] In 2013 these numbers had increased to 160,521 and 53,252.[90] However, about a half of IVF pregnancies result in multiple-birth deliveries, which in turn are associated with an increase in both morbidity and mortality of the mother and the infant. Causes for this include increased maternal blood pressure, premature birth and low birth weight. In addition, more women are waiting longer to conceive and seeking ART.[90]

Poster addressing the 2014 London Girl Summit dealing with FGM and Child Marriage

Child marriage (including union or cohabitation)[91] is defined as marriage under the age of eighteen and is an ancient custom. In 2010 it was estimated that 67 million women, then, in their twenties had been married before they turned eighteen, and that 150 million would be in the next decade, equivalent to 15 million per year. This number had increased to 70 million by 2012. In developing countries one third of girls are married under age, and 1:9 before 15.[92] The practice is commonest in South Asia (48% of women), Africa (42%) and Latin America and the Caribbean (29%). The highest prevalence is in Western and Sub-Saharan Africa. The percentage of girls married before the age of eighteen is as high as 75% in countries such as Niger (Nour, Table I).[11][92] Most child marriage involves girls. For instance in Mali the ratio of girls to boys is 72:1, while in countries such as the United States the ratio is 8:1. Marriage may occur as early as birth, with the girl being sent to her husbands home as early as age seven.[11]

There are a number of cultural factors that reinforce this practice. These include the child's financial future, her dowry, social ties and social status, prevention of premarital sex, extramarital pregnancy and STIs. The arguments against it include interruption of education and loss of employment prospects, and hence economic status, as well as loss of normal childhood and its emotional maturation and social isolation. Child marriage places the girl in a relationship where she is in a major imbalance of power and perpetuates the gender inequality that contributed to the practice in the first place.[93][94] Also in the case of minors, there are the issues of human rights, non-consensual sexual activity and forced marriage and a 2016 joint report of the WHO and Inter-Parliamentary Union places the two concepts together as Child, Early and Forced Marriage (CEFM), as did the 2014 Girl Summit (see below).[95] In addition the likely pregnancies at a young age are associated with higher medical risks for both mother and child, multiple pregnancies and less access to care[96][11][93] with pregnancy being amongst the leading causes of death amongst girls aged 15–19. Girls married under age are also more likely to be the victims of domestic violence.[92]

Urges all States to enact, enforce and uphold laws and policies aimed at preventing and ending child, early and forced marriage and protecting those at risk, and ensure that marriage is entered into only with the informed, free and full consent of the intending spouses (5 September 2014)

Amongst non-governmental organizations (NGOs) working to end child marriage are Girls not Brides,[106]Young Women's Christian Association (YWCA), the International Center for Research on Women (ICRW)[107] and Human Rights Watch (HRW).[108] Although not explicitly included in the original Millennium Development Goals, considerable pressure was applied to include ending child marriage in the successor Sustainable Development Goals adopted in September 2015,[105] where ending this practice by 2030 is a target of SDG 5 Gender Equality (see above).[109] While some progress is being made in reducing child marriage, particularly for girls under fifteen, the prospects are daunting.[110] The indicator for this will be the percentage of women aged 20–24 who were married or in a union before the age of eighteen. Efforts to end child marriage include legislation and ensuring enforcement together with empowering women and girls.[92][93][95][94] To raise awareness, the inaugural UN International Day of the Girl Child[a] in 2012 was dedicated to ending child marriage.[112]

Women's menstrual cycles, the approximately monthly cycle of changes in the reproductive system, can pose significant challenges for women in their reproductive years (the early teens to about 50 years of age). These include the physiological changes that can effect physical and mental health, symptoms of ovulation and the regular shedding of the inner lining of the uterus (endometrium) accompanied by vaginal bleeding (menses or menstruation). The onset of menstruation (menarche) may be alarming to unprepared girls and mistaken for illness. Menstruation can place undue burdens on women in terms of their ability to participate in activities, and access to menstrual aids such as tampons and "sanitary pads". This is particularly acute amongst poorer socioeconomic groups where they may represent a financial burden and in developing countries where menstruation can be an impediment to a girl's education.[113]

Equally challenging for women are the physiological and emotional changes associated with the cessation of menses (menopause or climacteric). While typically occurring gradually towards the end of the fifth decade in life marked by irregular bleeding the cessation of ovulation and menstruation is accompanied by marked changes in hormonal activity, both by the ovary itself (oestrogen and progesterone) and the pituitary gland (follicle stimulating hormone or FSH and luteinizing hormone or LH). These hormonal changes may be associated with both systemic sensations such as hot flashes and local changes to the reproductive tract such as reduced vaginal secretions and lubrication. While menopause may bring relief from symptoms of menstruation and fear of pregnancy it may also be accompanied by emotional and psychological changes associated with the symbolism of the loss of fertility and a reminder of aging and possible loss of desirability. While menopause generally occurs naturally as a physiological process it may occur earlier (premature menopause) as a result of disease or from medical or surgical intervention. When menopause occurs prematurely the adverse consequences may be more severe.[114][115]

Cardiovascular disease is the leading cause of death (30%) amongst women in the United States, and the leading cause of chronic disease amongst them, affecting nearly 40% (Gronowski and Schindler, Tables I and IV).[6][7][119] The onset occurs at a later age in women than in men. For instance the incidence of stroke in women under the age of 80 is less than that in men, but higher in those aged over 80. Overall the lifetime risk of stroke in women exceeds that in men.[27][28] The risk of cardiovascular disease amongst those with diabetes and amongst smokers is also higher in women than in men.[6] Many aspects of cardiovascular disease vary between women and men, including risk factors, prevalence, physiology, symptoms, response to intervention and outcome.[119]

Women and men have approximately equal risk of dying from cancer, which accounts for about a quarter of all deaths, and is the second leading cause of death. However the relative incidence of different cancers varies between women and men. In the United States the three commonest types of cancer of women in 2012 were lung, breast and colorectal cancers. In addition other important cancers in women, in order of importance, are ovarian, uterine (including endometrial and cervical cancers (Gronowski and Schindler, Table III).[6][120] Similar figures were reported in 2016.[121] While cancer death rates rose rapidly during the twentieth century, the increase was less and later in women due to differences in smoking rates. More recently cancer death rates have started to decline as the use of tobacco becomes less common. Between 1991 and 2012, the death rate in women declined by 19% (less than in men). In the early twentieth century death from uterine (uterine body and cervix) cancers was the leading cause of cancer death in women, who had a higher cancer mortality than men. From the 1930s onwards, uterine cancer deaths declined, primarily due to lower death rates from cervical cancer following the availability of the Papanicolaou (Pap) screening test. This resulted in an overall reduction of cancer deaths in women between the 1940s and 1970s, when rising rates of lung cancer led to an overall increase. By the 1950s the decline in uterine cancer left breast cancer as the leading cause of cancer death till it was overtaken by lung cancer in the 1980s. All three cancers (lung, breast, uterus) are now declining in cancer death rates (Siegel et al. Figure 8),[121] but more women die from lung cancer every year than from breast, ovarian, and uterine cancers combined. Overall about 20% of people found to have lung cancer are never smokers, yet amongst nonsmoking women the risk of developing lung cancer is three times greater than amongst men who never smoked.[119]

In addition to mortality, cancer is a cause of considerable morbidity in women. Women have a lower lifetime probability of being diagnosed with cancer (38% vs 45% for men), but are more likely to be diagnosed with cancer at an earlier age.[7]

Breast cancer is the second most common cancer in the world and the most common among women. It is also among the ten most common chronic diseases of women, and a substantial contributor to loss of quality of life (Gronowski and Schindler, Table IV).[6] Globally, it accounts for 25% of all cancers. In 2016, breast cancer is the most common cancer diagnosed among women in both developed and developing countries, accounting for nearly 30% of all cases, and worldwide accounts for one and a half million cases and over half a million deaths, being the fifth most common cause of cancer death overall and the second in developed regions. Geographic variation in incidence is the opposite of that of cervical cancer, being highest in Northern America and lowest in Eastern and Middle Africa, but mortality rates are relatively constant, resulting in a wide variance in case mortality, ranging from 25% in developed regions to 37% in developing regions, and with 62% of deaths occurring in developing countries.[17][122]

Globally, cervical cancer is the fourth commonest cancer amongst women, particularly those of lower socioeconomic status. Women in this group have reduced access to health care, high rates of child and forced marriage, parity, polygamy and exposure to STIs from multiple sexual contacts of male partners. All of these factors place them at higher risk.[11] In developing countries, cervical cancer accounts for 12% of cancer cases amongst women and is the second leading cause of death, where about 85% of the global burden of over 500,000 cases and 250,000 deaths from this disease occurred in 2012. The highest incidence occurs in Eastern Africa, where with Middle Africa, cervical cancer is the commonest cancer in women. The case fatality rate of 52% is also higher in developing countries than in developed countries (43%), and the mortality rate varies by 18-fold between regions of the world.[123][17][122]

Cervical cancer is associated with human papillomavirus (HPV), which has also been implicated in cancers of the vulva, vagina, anus, and oropharynx. Almost 300 million women worldwide have been infected with HPV, one of the commoner sexually transmitted infections, and 5% of the 13 million new cases of cancer in the world have been attributed to HPV.[124][75] In developed countries, screening for cervical cancer using the Pap test has identified pre-cancerous changes in the cervix, at least in those women with access to health care. Also an HPV vaccine programme is available in 45 countries. Screening and prevention programmes have limited availability in developing countries although inexpensive low technology programmes are being developed,[125] but access to treatment is also limited.[123] If applied globally, HPV vaccination at 70% coverage could save the lives of 4 million women from cervical cancer, since most cases occur in developing countries.[6]

By contrast, ovarian cancer, the leading cause of reproductive organ cancer deaths, and the fifth commonest cause of cancer deaths in women in the United States, lacks an effective screening programme, and is predominantly a disease of women in industrialised countries. Because it is largely asymptomatic in its earliest stages, more than 50% of women have stage III or higher cancer (spread beyond the ovaries) by the time they are diagnosed, with a consequent poor prognosis.[121][6]

Almost 25% of women will experience mental health issues over their lifetime.[126] Women are at higher risk than men from anxiety, depression, and psychosomatic complaints.[17] Globally, depression is the leading disease burden. In the United States, women have depression twice as often as men. The economic costs of depression in American women are estimated to be $20 billion every year. The risks of depression in women have been linked to changing hormonal environment that women experience, including puberty, menstruation, pregnancy, childbirth and the menopause.[119] Women also metabolise drugs used to treat depression differently to men.[119][127] Suicide rates are less in women than men (<1% vs. 2.4%),[27][28] but are a leading cause of death for women under the age of 60.[17]

The prevalence of Alzheimer's Disease in the United States is estimated at 5.1 million, and of these two thirds are women. Furthermore, women are far more likely to be the primary caregivers of adult family members with depression, so that they bear both the risks and burdens of this disease. The lifetime risk for a woman of developing Alzeimer's is twice that of men. Part of this difference may be due to life expectancy, but changing hormonal status over their lifetime may also play a par as may differences in gene expression.[119] Deaths due to dementia are higher in women than men (4.5% of deaths vs. 2.0%).[6]

Osteoporosis ranks sixth amongst chronic diseases of women in the United States, with an overall prevalence of 18%, and a much higher rate involving the femur, neck or lumbar spine amongst women (16%) than men (4%), over the age of 50 (Gronowski and Schindler, Table IV).[6][7][128] Osteoporosis is a risk factor for bone fracture and about 20% of senior citizens who sustain a hip fracture die within a year.[6][129] The gender gap is largely the result of the reduction of estrogen levels in women following the menopause. Hormone Replacement Therapy (HRT) has been shown to reduce this risk by 25–30%,[130] and was a common reason for prescribing it during the 1980s and 1990s. However the Women's Health Initiative (WHI) study that demonstrated that the risks of HRT outweighed the benefits[131] has since led to a decline in HRT usage.

Anaemia is a major global health problem for women.[132] Women are affected more than men, in which up to 30% of women being found to be anaemic and 42% of pregnant women. Anaemia is linked to a number of adverse health outcomes including a poor pregnancy outcome and impaired cognitive function (decreased concentration and attention).[133] The main cause of anaemia is iron deficiency. In United States women iron deficiency anaemia (IDA) affects 37% of pregnant women, but globally the prevalence is as high as 80%. IDA starts in adolescence, from excess menstrual blood loss, compounded by the increased demand for iron in growth and suboptimal dietary intake. In the adult woman, pregnancy leads to further iron depletion.[6]

" any act of gender-based violence that results in, or is likely to result in, physical, sexual or mental harm or suffering to women, including threats of such acts, coercion or arbitrary deprivation of liberty, whether occurring in public or in private life." (United Nations, Declaration on the Elimination of Violence against Women, 1993)

Violence against women may take many forms, including physical, sexual, emotional and psychological and may occur throughout the life-course. Structural violence may be embedded in legislation or policy, or be systematic misogyny by organisations against groups of women. Perpetrators of personal violence include state actors, strangers, acquaintances, relatives and intimate partners and manifests itself across a spectrum from discrimination, through harassment, sexual assault and rape, and physical harm to murder (femicide). It may also include cultural practices such as female genital cutting.[135][136]

Non-fatal violence against women has severe implications for women’s physical, mental and reproductive health, and is seen as not simply isolated events but rather a systematic pattern of behaviour that both violates their rights but also limits their role in society and requires a systematic approach.[137]

The World Health Organisation (WHO) estimates that 35% of women in the world have experienced physical or sexual violence over their lifetime and that the commonest situation is intimate partner violence. 30% of women in relationships report such experience, and 38% of murders of women are due to intimate partners. These figures may be as high as 70% in some regions.[138] Risk factors include low educational achievement, a parental experience of violence, childhood abuse, gender inequality and cultural attitudes that allow violence to be considered more acceptable.[139]

Violence was declared a global health priority by the WHO at its assembly in 1996, drawing on both the United Nations Declaration on the elimination of violence against women (1993)[134] and the recommendations of both the International Conference on Population and Development (Cairo, 1994) and the Fourth World Conference on Women (Beijing, 1995)[140] This was followed by its 2002 World Report on Violence and Health, which focusses on intimate partner and sexual violence.[141] Meanwhile, the UN embedded these in an action plan when its General Assembly passed the Millennium Declaration in September 2000, which resolved inter alia "to combat all forms of violence against women and to implement the Convention on the Elimination of All Forms of Discrimination against Women".[142] One of the Millennium Goals (MDG 3) was the promotion of gender equality and the empowerment of women,[143] which sought to eliminate all forms of violence against women as well as implementing CEDAW.[101] This recognised that eliminating violence, including discrimination was a prerequisite to achieving all other goals of improving women's health. However it was later criticised for not including violence as an explicit target, the "missing target".[144][85] In the evaluation of MDG 3, violence remained a major barrier to achieving the goals.[31][37] In the successor Sustainable Development Goals, which also explicitly list the related issues of discrimination, child marriage and genital cutting, one target is listed as "Eliminate all forms of violence against all women and girls in the public and private spheres" by 2030.[109][145][138]

UN Women believe that violence against women "is rooted in gender-based discrimination and social norms and gender stereotypes that perpetuate such violence", and advocate moving from supporting victims to prevention, through addressing root and structural causes. They recommend programmes that start early in life and are directed towards both genders to promote respect and equality, an area often overlooked in public policy. This strategy, which involves broad educational and cultural change, also involves implementing the recommendations of the 57th session of the UN Commission on the Status of Women[146] (2013).[147][148][149] To that end the 2014 UN International Day of the Girl Child was dedicated to ending the cycle of violence.[112] In 2016, the World Health Assembly also adopted a plan of action to combat violence against women, globally.[150]

Changes in the way research ethics was visualised in the wake of the Nuremberg Trials (1946), led to an atmosphere of protectionism of groups deemed to be vulnerable that was often legislated or regulated. This resulted in the relative underrepresentation of women in clinical trials. The position of women in research was further compromised in 1977, when in response to the tragedies resulting from thalidomide and diethylstilbestrol (DES), the United States Food and Drug Administration (FDA) prohibited women of child bearing years from participation in early stage clinical trials. In practice this ban was often applied very widely to exclude all women.[151][152] Women, at least those in the child bearing years, were also deemed unsuitable research subjects due to their fluctuating hormonal levels during the menstrual cycle. However, research has demonstrated significant biological differences between the sexes in rates of susceptibility, symptoms and response to treatment in many major areas of health, including heart disease and some cancers. These exclusions pose a threat to the application of evidence-based medicine to women, and compromise to care offered to both women and men.[6][153]

The increasing focus on Women's Rights in the United States during the 1980s focused attention on the fact that many drugs being prescribed for women had never actually been tested in women of child-bearing potential, and that there was a relative paucity of basic research into women's health. In response to this the National Institutes of Health (NIH) created the Office of Research on Women's Health (ORWH)[154] in 1990 to address these inequities. In 1993 the National Institutes of Health Revitalisation Act officially reversed US policy by requiring NIH funded phase III clinical trials to include women.[119] This resulted in an increase in women recruited into research studies. The next phase was the specific funding of large scale epidemiology studies and clinical trials focussing on women's health such as the Women's Health Initiative (1991), the largest disease prevention study conducted in the US. Its role was to study the major causes of death, disability and frailty in older women.[155] Despite this apparent progress, women remain underepresented. In 2006 women accounted for less than 25% of clinical trials published in 2004,[156] A follow up study by the same authors five years later found little evidence of improvement.[157] Another study found between 10–47% of women in heart disease clinical trials, despite the prevalence of heart disease in women.[158] Lung cancer is the leading cause of cancer death amongst women, but while the number of women enrolled in lung cancer studies is increasing, they are still far less likely to be enrolled than men.[119]

One of the challenges in assessing progress in this area is the number of clinical studies that either do not report the gender of the subjects or lack the statistical power to detect gender differences.[156][159] These were still issues in 2014, and further compounded by the fact that the majority of animal studies also exclude females or fail to account for differences in sex and gender. for instance despite the higher incidence of depression amongst women, less than half of the animal studies use female animals.[119] Consequently, a number of funding agencies and scientific journals are asking researchers to explicitly address issus of sex and gender in their research.[160][161]

A related issue is the inclusion of pregnant women in clinical studies. Since other illnesses can exist concurrently with pregnancy, information is needed on the response to and efficacy of interventions during pregnancy, but ethical issues relative to the fetus, make this more complex. This gender bias is partly offset by the iniation of large scale epidemiology studies of women, such as the Nurses' Health Study (1976),[162]Women's Health Initiative[163] and Black Women's Health Study.[164][6]

Women have also been the subject of abuse in health care research, such as the situation revealed in the Cartwright Inquiry in New Zealand (1988), in which research by two feminist journalists[165] revealed that women with cervical abnormalities were not receiving treatment, as part of an experiment. The women were not told of the abnormalities and several later died.[166]

Internationally, many United Nations agencies such as the World Health Organization (WHO), United Nations Population Fund (UNFPA)[171] and UNICEF[172] maintain specific programs on women's health, or maternal, sexual and reproductive health.[1][173] In addition the United Nations global goals address many issues related to women's health, both directly and indirectly. These include the 2000 Millennium Development Goals (MDG)[142][43] and their successor, the Sustainable Development Goals adopted in September 2015,[47] following the report on progress towards the MDGs (The Millennium Development Goals Report 2015).[174][37] For instance the eight MDG goals, eradicating extreme poverty and hunger, achieving universal primary education, promoting gender equality and empowering women, reducing child mortality rates, improving maternal health, combating HIV/AIDS malaria and other diseases, ensuring environmental sustainability, and developing a global partnership for development, all impact on women's health,[43][11] as do all seventeen SDG goals,[47] in addition to the specific SDG5: Achieve gender equality and empower all women and girls.[109][175]

Research is a priority in terms of improving women's health. Research needs include diseases unique to women, more serious in women and those that differ in risk factors between women and men. The balance of gender in research studies needs to be balanced appropriately to allow analysis that will detect interactions between gender and other factors.[6] Gronowski and Schindler suggest that scientific journals make documentation of gender a requirement when reporting the results of animal studies, and that funding agencies require justification from investigators for any gender inequity in their grant proposals, giving preference to those that are inclusive. They also suggest it is the role of health organisations to encourage women to enroll in clinical research. However, there has been progress in terms of large scale studies such as the WHI, and in 2006 the Society for Women's Health Research founded the Organization for the Study of Sex Differences (OSSD) and the journal Biology of Sex Differences to further the study of sex differences.[6]

Research findings can take some time before becoming routinely implemented into clinical practice. Clinical medicine needs to incorporate the information already available from research studies as to the different ways in which diseases affect women and men. Many "normal" laboratory values have not been properly established for the female population separately, and similarly the "normal" criteria for growth and development. Drug dosing needs to take gender differences in drug metabolism into account.[6]

Globally, women's access to health care remains a challenge, both in developing and developed countries. In the United States, before the Affordable Health Care Act came into effect, 25% of women of child bearing age lacked health insurance.[176] In the absence of adequate insurance, women are likely to avoid important steps to self care such as routine physical examination, screening and prevention testing, and prenatal care. The situation is aggravated by the fact that women living below the poverty line are at greater risk of unplanned pregnancy, unplanned delivery and elective abortion. Added to the financial burden in this group are poor educational achievement, lack of transportation, inflexible work schedules and difficulty obtaining child care, all of which function to create barriers to accessing health care. These problems are much worse in developing countries. Under 50% of childbirths in these countries are assisted by healthcare providers (e.g.midwives, nurses, doctors) which accounts for higher rates of maternal death, up to 1:1,000 live births. This is despite the WHO setting standards, such as a minimum of four antenatal visits.[177] A lack of healthcare providers, facilities, and resources such as formularies all contribute to high levels of morbidity amongst women from avoidable conditions such as obstetrical fistulae, sexually transmitted diseases and cervical cancer.[6]

These challenges are included in the goals of the Office of Research on Women's Health, in the United States, as is the goal of facilitating women's access to careers in biomedicine. The ORWH believes that one of the best ways to advance research in women's health is to increase the proportion of women involved in healthcare and health research, as well as assuming leadership in government, centres of higher learning, and in the private sector.[155] This goal acknowledges the glass ceiling that women face in careers in science and in obtaining resources from grant funding to salaries and laboratory space.[178] The National Science Foundation in the United States states that women only gain half of the doctorates awarded in science and engineering, fill only 21% of full-time professor positions in science and 5% of those in engineering, while earning only 82% of the remuneration their male colleagues make. These figures are even lower in Europe.[178]

Gahagan, Jacqueline (15 August 2016). "Commentary on the new sex and gender editorial policy of the Canadian Journal of Public Health". Canadian Journal of Public Health. 107 (2): 140. doi:10.17269/cjph.107.5584. Lay summary – Jon Tattrie. Canadian Journal of Public Health tells researchers to address sex, gender in trials: Research 'excluding 50 per cent of the population' isn't best return for taxpayers, says Jacqueline Gahagan. Canadian Broadcasting Corporation News: Nova Scotia (7 December 2016).

WHO (1948). "WHO definition of Health". Archived from the original(Preamble to the Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19–22 June 1946; signed on 22 July 1946 by the representatives of 61 States (Official Records of the World Health Organization, no. 2, p. 100) and entered into force on 7 April 1948.) on 7 July 2016. Retrieved 6 July 2016., in WHO (2016)